1/*
2 * OpenRISC module.c
3 *
4 * Linux architectural port borrowing liberally from similar works of
5 * others.  All original copyrights apply as per the original source
6 * declaration.
7 *
8 * Modifications for the OpenRISC architecture:
9 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
10 *
11 *      This program is free software; you can redistribute it and/or
12 *      modify it under the terms of the GNU General Public License
13 *      as published by the Free Software Foundation; either version
14 *      2 of the License, or (at your option) any later version.
15 */
16
17#include <linux/moduleloader.h>
18#include <linux/elf.h>
19
20int apply_relocate_add(Elf32_Shdr *sechdrs,
21		       const char *strtab,
22		       unsigned int symindex,
23		       unsigned int relsec,
24		       struct module *me)
25{
26	unsigned int i;
27	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
28	Elf32_Sym *sym;
29	uint32_t *location;
30	uint32_t value;
31
32	pr_debug("Applying relocate section %u to %u\n", relsec,
33		 sechdrs[relsec].sh_info);
34	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
35		/* This is where to make the change */
36		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
37			+ rel[i].r_offset;
38
39		/* This is the symbol it is referring to.  Note that all
40		   undefined symbols have been resolved.  */
41		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
42			+ ELF32_R_SYM(rel[i].r_info);
43		value = sym->st_value + rel[i].r_addend;
44
45		switch (ELF32_R_TYPE(rel[i].r_info)) {
46		case R_OR32_32:
47			*location = value;
48			break;
49		case R_OR32_CONST:
50			*((uint16_t *)location + 1) = value;
51			break;
52		case R_OR32_CONSTH:
53			*((uint16_t *)location + 1) = value >> 16;
54			break;
55		case R_OR32_JUMPTARG:
56			value -= (uint32_t)location;
57			value >>= 2;
58			value &= 0x03ffffff;
59			value |= *location & 0xfc000000;
60			*location = value;
61			break;
62		default:
63			pr_err("module %s: Unknown relocation: %u\n",
64			       me->name, ELF32_R_TYPE(rel[i].r_info));
65			break;
66		}
67	}
68
69	return 0;
70}
71